macknight



J OIIN IV. HACKNIGHT, OF NEWT YORK, N. Y,

METHOD OF LAYING ARTlFlClAL PAVEMENT.

SPECIFICATION forming part of Letters Patent No. 401,447, dated. April16, 1889. Application filed January 2, 1889. Serial No. 295,197. (Nomodel.)

To all whom it may concern.'

Be it known that I, JOHN WT., MAQKNIGHT, of New Yer c city, New York,have invented an Improved Method of Laying Artificial Pavement, of whichthe following is a specifieation.

This invention has reference to an improved method of laying anartificial pavement for the roadway between the curbs. It has for itsobject, more particularly, to produce a noiseless pavement which offersa secure foot ing tor the horses, and in which the yielding materialbetween the artificial-stone strips is securely held in place, and isprevented from being gradually trod into the ground.

In the accompanying drawings, Figure l is a vertical transverse sectionof an artificial pavement laid according to my method. Fig. 2 is a topview of the same, partly in longitudinal section. Fig. 3 is a cross-section through the upper layers on the line 1*,Fig. l, with the joistsin place.

In laying the artiiieial pavement, I iirst form a bottom layer of rocks,a, placed on edge. Above these I form a layer of coalashes, l). Thesetwo layers are made to extend over any desired length of the roadway,perhaps a block, from curb to curb. Next I form the third layer offlint-ic concrete; but this layer I do not form in a continuous section,but in a series of parallel equidistant strips or sections, c c,extending from curb to curb. The spaces between the sections c arefilled in, in manner hereinafter described, after the top dressing uponsections e has been completed. Upon the sections c, Iplace from curb tocurb, while these sections are still moist, a series of joists, d d,preferably about four inches apart and one inch wide. Near each edge ofthe sections c, I place upon it a T-shaped joist, d. Next I fill in thespaces between the joists with a wet mixture of trap-roei; and Port-landcement Preterably two grades of trap-rock are used-the coarser one forthe bottom e and the iiner one for the top f. The layers c f are thusoomposed of the same material, only that the bottom layer is somewhateoarser. The bottom layer, e, being nioist and the ilintic concretelayer c being moist, these two layers will unite firmly with each otherinto one adherentsolid massa The sections o, with their top layer, c f,being thus far completed, the end joists, d cl, are removed, and thespaces between the sections e c are filled in in the same manner as hasbeen described with relation to sections c--that is to say, sections cof flintic concrete are formed between sections c c, and upon them thejoists d are placed. Of course the end joists, d', are not needed. Nextthe two top layers, e"

f", are filled in between the top layers, e f, of

the adjoining completed sections. It will be seen that owing to theT-shaped end j oists, CZ', lap-j oints will be formed between thevarious sections of pavement, which prevent settling along the lines gof the joints. The pavement being thus far completed, the joists CZ areall removed, and the grooves thus formed are filled in with a yieldingmixture, 7L, composed of about thirty parts of broken trap-rock, gravel,or slag, one partof crude petroleum, and five parts of asphaltum. Toform this mixture, the trapo'ock, gravel, or slag is rst dried, and ismixed with the petroleum and asphaltum while the latter are heated.

The mixture will lill the grooves up to the surface, and will partlypercolate through the sides of the grooves into the top layers, to befirmly joined therewith 5 but, as the top layers are firmly united tothe tlintic concrete layers c c', the bottom of the grooves are solidlyclosed, and the mixture 7L will not be liable to be pressed down and outofthe grooves by wear.

Thus a pavement is formed that offers a proper hold for the horses, andwhich at the same time will last for a very long time.

Another feature of this pavement is that at the lap-joints between thesections of top dressing thesel sections will not unite-that is, at thelines g the pavement will be disconnected. Thus any one section may bebroken away partly or entirely without disturbing the adjoiningsections.

The method of laying an artificial pavement, which consists in formingcontinuous bottom layers of rook and ashes, forming a ing the remainingjoists, and illing in the series of parallel sections of iiintioconcrete gooves with a yielding mixture, substanupon them, placingjoists upon these sections, tially as specified.

lling in the spaces between the joists with JOHN W. MACKNIGHT. 5 amixture of ilintio concrete and cement, re- Witnesses:

moving the end joisns and filling in the ini F. V. BRIESEN,

tervening spaces in a similar manner, remov- HENRY E. ROEDER.

